The recording method is well known which comprises the steps of exposing to a high density energy light such as a laser light, an image forming material, whereby a part of the material is deformed, released, burnt or evaporated and removed. This method is a dry process in which a processing solution containing a chemical is not employed, and only the exposed portions are melt-deformed, released or evaporated, which has an advantage resulting in high contrast. This method is used for an optical recording material such as a resist material, an optical disc or an image forming material obtaining a visual image. This image forming method hereinafter is defined as an image forming method according to abrasion.
Such an image forming method according to abrasion is different from a heat-fusible image transfer image forming method in the following points: The heat-fusible image transfer image forming method comprises the steps of providing an image forming layer on a support, the image forming layer containing a colorant and a thermoplastic resin or wax having a low melting or softening point; imagewise heating the image forming layer directly or indirectly through the support to the melting or softening point or more, whereby adhesion between the image forming layer and the support is reduced; and transferring the image forming layer at heated portions to an image receiving sheet. In this method, when the heated image forming layer is cooled before transfer, the adhesion before the heating is recovered, which means a reversible heat property change. On the other hand, the image forming method according to abrasion shows an irreversible change that the image forming layer is destroyed or deformed.
Regarding the image forming method according to abrasion, Japanese Patent O.P.I. Publication Nos. 59-5447, 59-10563, and 62-115153 disclose a method in which a binder resin is photodegraded by a pattern exposure to form a resist, Japanese Patent O.P.I. Publication Nos. 55-132536, 57-27788, and 57-103137 disclose a method in which a thin inorganic compound layer provided by evaporation-deposit is exposed to record information by melt-deformation, Japanese Patent O.P.I. Publication Nos. 64-56591, 1-99887, and 6-40163 disclose a method in which a colored binder resin is removed by light heat conversion to record information, and U.S. Pat. No. 4,245,003 discloses an image forming material comprising an image forming layer containing graphite or carbon black.
In PCT Patent No. 4-506709/1992, Japanese Patent O.P.I. Publication No. 6-18290/1994, and U.S. Pat. Nos. 5,156,938, 5,171,650 and 5,256,506 is disclosed an image forming material comprising a light heat converting substance capable of converting absorbed laser light energy to heat energy and a binder capable of being degraded due to heat.
In PCT Patent No. 4-506709/1992, Japanese Patent O.P.I. and U.S. Pat. Nos. 5,156,938, 5,171,650 and 5,256,506 is disclosed an image forming method which receives, on an image receiving material, an image forming layer to have been degraded and released. According to these, the scatter in air of fine powder of the image forming layer, which is produced due to abrasion, is solved.
However, the conventional image receiving material itself has an effect restraining the above abrasion phenomena, and in order to obtain an image with sufficient density and resolving power, high exposure energy is necessary, resulting in problems that an image forming apparatus is large-sized and increased in its manufacturing cost.
Further, in Japanese Patent O.P.I. Publication Nos. 4-327982/1992 and 4-327983/1992 is disclosed an image forming method comprising the steps of (a) exposing to a laser light an image forming material comprising a support and provided thereon, a light heat converting layer, which is also an evaporation layer, containing a light heat converting substance, and a colorant layer in that order, (b) superposing an image receiving material having a heat fusible layer on the image forming layer, and (c) peeling the image receiving material from the image forming layer to form an image. However, this image receiving material has a problem in that on peeling the image receiving material, a part of a substance in the the fusible layer remains with abraded image forming layer on the support, resulting in stain in the image forming material. Further, there are problems in that image defects such as scratches occur on the surface of the image forming materials after forming an image, which occur due to friction among them, or components in the image forming layer are dissolved in an organic solvent contained in film cleaner for graphic arts film.
As disclosed in Japanese Patent O.P.I. Publication No. 60-255491, a technique providing an image protective layer on an image forming layer is known in order to enhance image durability. When the image forming layer is thick, the image durability is enhanced but high exposure energy for recording an image is necessary and resolving power is lowered. Further, there are limitations that when an image forming layer coating solution is coated on the image forming layer coated on a support employing an image forming layer coating organic solvent solution, the image forming layer coating solution must be a water soluble resin solution or a water dispersible resin dispersion. This is disadvantageous in selecting a resin for the image protective layer.
As disclosed in Japanese Patent Publication No. 7-25202 (support/recording layer/image protective layer), there is description of a technique employing a coating solution in which a thermoplastic resin is dissolved in a specific solvent whereby solvent resistance is improved. However, this technique does not solve a problem of sensitivity lowering.